sayyârak-e kaltâvande, ~ kaltâvgar
An asteroid whose rotational motion does not take place about its → principal axis. Such a behavior can be interpreted as a composition of two or more rotational periods, and described mathematically by a two dimensional → Fourier series (Pravec et al. 2005, Icarus, 173, 108).
The term was first used by A. W. Harris, 1994, Icarus, 107, 209. → tumble; → asteroid.